Single plate multiple photographic reproduction



Jan. 3, 1933. R. R. ROBERTSON ,5

SINGLE PLATE MULTIPLE PHOTOGRAPHIC REPRODUCTION File'd June 27, 1.929 6Sheets-Sheet l @Mif Jan. 3, 1933. R. R. ROBERTSON SINGLE PLATE MULTIPLEPHOTOGRAPHIG REPRODUCTION 6 Sheets-Sheet 5 Filed June 27, 1929 71 foi aior via 44,;

l i I 1 Qf a 1 Jan. 3, 1933. R. R. ROBERTSON 1,892,683

SINGLE PLATE MULTI PLE PHOTOGRAPHIC REPRODUCTION Filed June 27, 1929 6Sheets-Sheet 4 Wit? 7501562 6]? jobs/$070- Jan. 3, 1933. R. R. ROBERTSON1,392,683

SINGLE PLATE MULTIPLE PHOTOGRAPHIC REPRODUCTION Filed June 27, 1929 6Sheets-Sheet 5 Merl/221 j 0681 121266030);

Jan. 3, 1933. R. R. ROBERTSON SINGLE PLATE MULTIPLE PHOTOGRAPHICREPRODUCTION 6 Sheets-Sheet 6 Filed June 27. 1929 o o oo o o 00 O0 0 o oo oo oo oo 00 o e 000 00 o 0 0o 0 o o o 0000 00 oo 0ooooooooooooooooooooooo 0 00 0 0o 00 00 9 a 0 0 0'0 00 o o so 0 o 00 o oo 00 GO 0 o o o o o oo o o oo o 0 oo oo oo o Q00 00 oo 0 o 00 o e o e oo o 0 so 0 o o o o 000 00 o o o o oo o o o o o o 00 0 00 Q o o 00 0G 0 oo o o 0 Www Patented Jan. 3, 1933 UNITED STATES nom'r-a. nomrsox, ornvmsron, rumors anion: 'rm'ra mmrrrmi rnoroemmc aaraonucrron'Applleaflen and June, me. Serial so. 374,250.

' This invention relates to re roduction, by 3 the procem ofphotography, copy sub ects, "for instance, photographic reproductionpracticed as a step in the art'of producing printing forms, and has forits object to economize in time and expense of materials usedin.;performin the step which relates particularly to ma ing negatives ofa plub rality offcopy subjects of printing forms, it has been necessa totake each copy subject and photograp it upon a special plate which isthen handled and treated through the remainin steps of of the process,with the result that e greater portion of the work, being multipliedaccordmg to the number of copy subjects handled,

was very expensive in point of time and materials consumed, and veryuneconomical in the consumption of the sensitized photographic plate orfilm that had to be subjected.

to exposure in producing the negative. The resent invention proceedsupon the i5 princip e of photographing a considerable number of copy subects all upon one and the same sensitized surface, under conditionswhich afford the same ran e of independent treatment of the copy subect, as to size and intensity of exposure, as if a separate plate wereused for each copy subject. Collateral features of the invention have todo with a j method of indicating by previously formed plat or chart, theprecise arrangement of ex posures upon the sensitized surface thatshould be made in order to carry out the 'proc .ess mosteconomically;also with apparatus for accurately locating copy subjects upon a a copyholder in positions corresponding to the i chart, and correspondinglylocating the image upon the sensitized surface within the camera; alsowith means for effecting necessary adjustments of the lens of the cameratqinsure proper projection of the image upon a predetermined limitedspace of the sensitized surface; also with means for screening, at will,any restricted portion of a sensitized surface with effective screeningand protection of the remainder of the surface against light; also withmeans whereby the several engaging the sheet to be held. Heretofore, Inmaking negatives of copy subjects as a preliminary to the productionfeatures of the invention may be adapted to photograph? through means ofa aratus aving the coal axis of the lens para el with the surface of thecop holder; and with improved means for hol ing the'copy subject or'a'sensitized film or sheet upon a supporting surface or any selectedportion thereof without the use of means penetrating orotherwise In theaccompanying drawings+ 1 v Figure 1 is a side e'levation of a commercialcamera of known form in which the several features of my invention'areembodied.

Figure 2 is a front elevation of the same with the copy holder removed.v n

Figure 3 is a section on the line 3w-3a: of Figures 1, 4, and 5.: YFigure 4 is a sectionyon the line 407-42 of Figures 2, 3,5, and 12.

Figure 5 is a s'ection'on the'line 5:v'-5:v of Figures 3, 4, and 12. a

Figure 6 is a detail view showing one method of holding a copy subjector a sensitized film or sheet to a supporting surface by air suction.

Figure '7 is a section on the line/(M702 of Fi re 8.- n

I igure 8 is a section on the line Bar-8230f Fi re 7. Figure 9 is afront view ofthe copy holder shown in Figure 1. i, p I

Figure 10 is a face'view of the guide chart previously made up toindicate the location of copy subjects in a manner to insure mosteconomical arrangement of their images upon the sensitized surface andas a preliminary to which corresponding placement of the copy subjectsupon the copy holder of Figure 9 must be resorted to.

Figurell is a view showin the arrangement of the copying camera wit itsfocal axis parallel to the plane of the copy holder.

Figure 12 is a view corresponding to Figure 3 showing the means throughwhich to effect adjustment of the lens required in using the arrangementof Figure 11.

Figure 13 is a view illustrating the appli- 'cation of the invention toa darkroom into which an immovable lens projects its beam, with aconstantly positioned axis upon a senferre sitized surface supportedwith universal adjustment in order to bring any desired restrictedportion of the surface under the influence of the beam.

Figure 14 is a detail perspective view of the universally adjustablesupport for the sensitized surface in Figure 13; and

Figure 15 shows a modified construction of means for holding a sheetagainst a support through means of air suction without mutilation of thesheet.

Referring first to the illustrative embodiment of the inventiondisclosed in Figures 1 to 10 inclusive, where the invention is shownapplied to a copying camera operating with the axis of the lensperpendicular to the plane of the copy'subject, 1 represents aconventional copy holder modified to embody that part of the presentinvention which has to do with facilitating the location of the copysubject on the holder in correspondence with the position which theimage is to occupy in the multiple subject photograph. 2 represents thestandard commercial copying camera modified according to the presentinvention to adapt it to shift its lens and expose limited ortions ofits sensitized surface in correspon ence with the required location ofeach image on the multiple negative to be produced. 3 represents a knownconstruction of carriage upon which the camera is mounted with suchmovement as is required for determining focal distance, and whichcarriage is preferably mounted in a known manner through the medium of abed 4 and shock absorbing suspension means 4a upon trucks 5; a gauge 6being provided to indicate the position of the carriageB upon the bed 4,which position may receive its fine ad j ustment through means of thehand wheel 7. 8 represents a compensating gauge indicating correfltivecarriage positions hereinafter re- 9 indicates, generally, the lens ofthe camera which, for purposes of that application of the inventionillustrated in Figures 1 to 10, is adapted to receive the horizontalmovement registered by the scale 9g traversed with the indicator 9h thatmoves with the lens, and the Vertical movement registered by the scale9e traversed by index 9} which partakes of the vertical movement of thelens; these movements of the lens being accompanied by shifting of lightscreens that protect the interior of the camera from the admission oflight otherwise than through the lens, for instance, vertically actinglight screens consisting of curtains 9a which extend from the top andbottom of the lens frame 9m to spring rollers 96, and horizontallyacting curtains 90 wh ch extend from spring rollers 9d to guideways 95which light-seal the edges of the curtains 90. It is to be noted thatthe rollers 97) on curtains 9a are mounted on or otherwise arranged totravel laterally with the guides 9a. By this arrangement, the lens 9 maybe moved laterally until its frame encounters one or the other of therollers 9d and while in either of these positions, or any positionintermediate thereof, may be moved vertically upon the guides 9i untilit encounters one or the other of the curtain rollers 91), or may bestop ed in any position inteJmediate thereof. Index 9f receives movementof the lens 9 through the medium of the cross bar 9k upon which theframe 9a: of lens 9 slides laterally, and the index is thus affectedonly by the vertical movements of the lens. Index 9h, as shown in Figure4, is supported between the guides 9i which have only lateral movement,and therefore this index partakes of lateral movements of the lens butis unaffected by vertical movements.

In order to protect the main area of the sensitized surface in thecamera while exposing a limited area of any desired dimensions to thebeam projected by the lens, I employ the arrangement shown in Figures 7and 8, wherein 10 represents the focus frame of the camera, 10arepresent top and bottom spring curtain rolls therein, and 10b representlaterally disposed spring curtain rolls. From the rolls 10a, curtains10c extend vertically upward and downward to controlling bn rs 10d towhich the free edges of said ourtains are united in a manner to controlsaid edges both as to vertical movement and the plane in which they lie;said rods 10d being extended outwardly through slots 10c in the focusframe 10 to slide bearings 10f arranged for manipulation and verticalmovement upon the vertical slide bars 10g. Similarly, curtains 10hextend from the rollers 10b laterally to controlling rods 102' which,like the rods 10d, extend through slots 10]: in the focal frame 10 toslide bearin 10l guided by horizontal slide rods 10m an through whichsaid vertical rods 10i may be manipulated. Spacing of the two pairs ofcurtains 10c and 10k establishes the confines of an exposure 1 area 11over the focal plane of the camera;

the pair 100 overlap the pair 10h so that whatever vertical dimensionmay be given to the exposure space 11 by regulation of the distancebetween the two rods 10d will leave the lateral confines of the exposurespace unchanged; and, similarly, whatever horizontal dimension may begiven to the space 11 by changing the distance between the bars 10i willnot affect the vertical dimension of said space. Moreover, since thebars 104, with any selected spacing, may be located anywhere within thevertical range of the focal area, and the bars 10:, with any selectedspacing, can be moved anywhere within the horizontal dimension of thefocal area, the evposure area defined by the four bars can be given anydesired rectangular fot'm and located in any part of the area.

escapes With a camera equipped for adjustment of its lens and limitationof exposure area as to dimensions and location, as above described,

it is merely necessary to appropriately I locate the copy subjects onthe copy holder 1 relatively large dimensions with independentnon-interfering exposures without danger of any of them becoming 1ight-struck, and thereby roduce an exposed plate or film upon which a lof the exposures can be developed simultaneously, with the expenditureof labor, time, and materials incident to but a single development The.negative thus produced can thereafter be used throughvarious steps ofthereproduction rocess incident to the making of printing orms or otherindustrial processes in a very economical manner. V

In order to facilitate accurate location of the copy subjects upon thecopy holder 1, and to do so pursuant to instructions of a skilleddirector who mayhave before him the entire grist of work to be donewithin a given period and thus be enabled to prescribe their. bestarrangement from an economical viewpoint, the invention provides fortheuse of a chart 12 (Figure 10), which is made up of rectangular formsdrawn to scale and representative of individual copy subjectsselectively grouped upon a sheet representative of the area of the copyholderas well as the area of the sensitized surface within the camera;and these prescribed figures, bearing suitable index characters,forinstance, A, B,

-C, D, etc. which are likewise borne upon the copy subject, andpreferably alsobeing marked with the dimensions of the reproductionimage to be projected onto the sensitized surface, are read off as tothe position to be selected for their counterparts on the copy holder byreference to marginalfigures extendingin two rectangular directions. Andto facilitate establishing the loci of the copy subjects on the. copvholder 1, the copy holder is provided with range bars 13, 14 mountedthrough means of slide bearings 15,16 upon a pair of vertical bars 17and a single horizontal bar 18. so thatif from among the copy subjectsfurnished to the cameraman, a subject marked A is selected', thecameraman looks at the chart 12 (Figure 10) and finds that this copysubject is to be'located on the, copy holder with its center defined by,the vertical line 2and a horizontal line intermediate of the horizon-.

copy holder 1, andthehorizontal bar 13 until it lies between the figures2 and 3 of the vertical series of figures on the copy holder 1;

and he attaches the copy subject A to the copy holder 1 with thegeometrical center of the copy subject behind the intersection of thebars 13 and 14, and, after returning the range bars to unobstructedposition, proceeds to make the exposure in the camera. But before makingthe exposure, the cameraman adjusts the lens 90f the camera until theindexes 9k and 9f point to corresponding figures to insure projection tothe proper limited exposure area on the sensitized surface, and adjuststhe slide bearings 10f, 101 (Figure?) until they, respectively,reach'positions defined by their ointers-lOfw, 101m in conjunction withgra uations 10fy, 10Z 1 on the back of the camera, as shown in dottedlines corresponding with marginal readings of the rectangle representingthe selected copy'subject on the chart 12; whereupon, the proper.distance adjustment of the lens 9 from the copy holder 1 having beenmade appropriate to the size indicatedon the rectangle A (or on the copysubject-if preferred), and the focal adjustment appropriate to saiddistance having been made with the focal plane ofthe camera, theexposure of the particularf'icopy subject is completed and another copysub- 1,

ject .is selected and theoperation repeated. This continues untilselectively defined, reduced exposure areas aggregating substantiallythe whole sensitized area have been used up, whereupon the plate or filmwill be removed and allof the-exposures are treated collectively in theensuing development," as well as in other steps in the industrialprocessfor which the exposures were made, for instance, in the process-ofproducing printing forms, the steps which consists in light-printingfrom the multiple subject photograph negative upon a surface to beetched, then etching said surface and otherwise finlshing the printingform before cutting up the etched plate into individualhalftones or thelike. Thus,.theprocedure is carried out with economy commensurate withthe use of a single manipulation for each step (in the presentinvention) vas compared with as many manipulations astherewere copysubjects (in the old method of procedure). i

As a convenient method of causing paper copy subjects to adhere to anyselected posi-* tion 'on the copy-holder without mutilation incident tothe usual mechanical means for attaching the paper, Figure 6 representsa copy holder consistingofa board 19 having perforations 20 and backedby an exhaust chamber21connected through suction hose 22 with a'fan 23driven by electric motor 24; suct on hose 22 and fan 23 being connectedby flexible connection 22a to. eliminate vibras tion,v r By permittingthe motor 24 to run constantly during the use of the copy holderandhaving the suction capacity of the fan 23 materially in excess of thetotal capacity of the perforations 20, sufiicient suction will boar 19while it is exist at all :times 'through'anyygrou'p of 1 per forationsQOto draw -a paper 'copyxaub ect *firml and smoothl to the surface of theing hoto bed.

If the invention is to em ied in a camera mounted with the axis of itslens rallel with the 'plane of the copy holder or instance, asillustratedin Figures Hand '12 wherein light is received from the copsubject on the cop holder 1a through .a reflecting prism 25, t e lens 9(Figure "12) will have itsframe 9o: sliding'vertically elgwonthe curtainbars 91' to positions registe by the as-already described with reference"to Figure 2, and similarly will'have its curtainbars 91' slidinghorizontall to give the lens a position registered by t e index 91;. Inother words, lens adjustment and construction permit ingthe same .may besubstantially asin the cm of the invention describedinvFigures 1 to 10,as also may be the curtain adjustments over the sensitized surfacein thefocus framelO. But the adjustment ofthe camera relativelyto the copyholder 10 will be horizontal travel-of the'lens 9, while deter- :min'the position of del1very.of.its.beam :upoii fiie sensitized surface,doesnot-ehanfie horizontallyin itsrelationrto the copy-ho er; it merevafiects focal distance, whichIis neutralized y correspond ad ustment ofthe camera as a whole thro the medium of its carriage 3a'upon'the 4a(Figure 11) through a corrective distance1 d f the com nsati 1 8,-t ereaings c .which w illypref e a l y fi in :figunes identical with thelaterally extending-'position-indicatthe chart 12 (Figure "10).

res on the chart .12 (Figure m). ore, all copy subjects-placed upontheholder 10 will be on the vertical line 1Y0! some other lineina-verticalplane centralto the reflector and perpendicular to the holdf-er1a,.and only vertical variations aretaken into accountin'positio copysubjects on the holder 1a, namely,-variations co d ing to verticaladjustments of the lens "9 rthe'vertical distance from top or'bottom ofthe vrestrictedexpcsuze areatselected within the camera. Thus, .to usethe camera disclosed in Figures'll and '12, a copywsubject will beplaced upon'theholder'la with its center approximately in ttheiverticalc line Y and behind the vertically'adjustable'cmm bar 18a when thelatter is occup a position in relation'to the vertical seri offigureszcalled for by the vertical marginal figures in marginal-figures in thechart '12 :(Figure 10) would be taken into account in; selecting :the

position of the indicatorrtlhlinFigure 12, but v 'notin determining theI location of the copy subject onithe holder :10 (Figure 511) ,becausein 'thisarmngement of the camera, the lens dcesnotxmovexin thedirectionof its axis (undifl'erentfor the reason that to '16 through the mediumof restricted areas of the Figure 13, manually placed overlappingcurtains or Fleas it be as a convenientway of c subject) operating withcopy subjects outside of the dark the thro h room and bringing the ima(and pre erably t 0 medium of the lens y prismatic reflector) through awlpll (for ind e dar room an stance, the top wall) of t projecting itupon a sensitized surface supported upon a table conveniently locatedfor observation and manipulation of the actinized film or late, as wellas protecting curtains manipu ated to selectively limit exposure areasas taught by the present invention.

In Figure 13, It represents the cop holder, 25a re resents a reflectingprism, an 9 a lens loca to receive light reflected from the copy holder1b and ro'ect the image through the top wall 26 ofthe dark room 27 toahorizontal focal table 28,

upon which may placed a sensitized film or plate to be exposed holder16. In this arrangement, lens 9, with its reflector 25, is preferablystationary on thetop wall 26 of the dark room 27 ;distance between-thelens and the copy holder which determines the size of re latedby movablymounting the copy he or ca 29 equipped with a known type "of distancegahgge "30; and focal adjustments are accomp ed by movement of the focustable 28 verticallythrough the medium of @118! justa mount' be" ui withsuch other aaeeaorie ia fis $1? dzs ig ble or convenient, such forinstance, as hand wheel 33 e mion 31, a bracket wheel 84 or table at anyadjustment, and colmterbalance for facilitating the the table. With anarrangement of from Figure 14, any desired subdivision of the surface ofthe table 28 may be resented in line with the focal axis of the ens 9 bymoving the base 36 on the sub-base 37 in one directiomfor instance, fromrigh Figure 13 and .the'table28 upon the base 36 the v r direction, forinstance, from front to rear as viewed in Figure 13. In thus us' thefeature of the wli ilfii hasto do with successively ex ing sensitizedsur ace in for turning light-intercepting boards or the like Ina be emloyed; or the arrangement shown could be bodily substituted for 28.

It is to be understood that the device shown be applied to the manner ofa sepaor film holder, as,

in 7 and 8 is to camera much after the rately constructed plate of copysubjects mounted upon the production, is

inion 81 with rack 82; such vertically add, as may be readily seenttoleftin present invention for instance, by placing it in rear of thecamera shown in Figure 1, or the camera shown in Figure 11, or otherwisecombining it with a camera having the laterally an vertically adjustablelens herein disclosed.

An alternative method of causing cop subjects or, if desired, sensitizedfilm, to a here to the plane surface of a holder without the use ofmechanical attachments, is illustrated in Figure 15, in which theperforated screen 19a is subject to the vacuum effect of a fan 23a solocated in relation to the opposite side of the screen from the sheet tobe held as to develop a partial vacuum sufficient to hold. the sheet inplace by suction.

The means shown in Figure 15 for holding a sheet or film is preferableto that shown in Fi ure 6, for the reason that, While in Fi re 6 theportion 220; of the air conduit is ru her and largely avoidstransmission of vibration from the motor to the holder, there is inFigure 15 a total absence of mechanical or vibration-transmittingconnection between the fan and the holder.

It is to be understood that in the cameras herein shown any desired 1iht-controlling cap maybe employed, such, or instance, as caps orshutters for the lens, as well as adjustable diaphragms, timingmechanism, and the like. These have not been disclosed because they formno part of the present invention. I

I claim:

The improvement in the art of photographically exposing difierentportions of a single sensitized surface to a corresponding number ofseparate copy subjects, which consists in preparing a master charthaving designated positions corresponding to the respective copysubjects, then mounting the copy subjects upon a copy board havingdesignations capable of defining ositions corresponding to the positionsesi ated upon the chart, then manipulating the lens of a 1 camera into aplurality of positions designated similarly to the positions of the copysubjects on the copy board and from which the lens projects images uponportions of the sensitized surface corresponding to the chart, andsuccessively exposin J the lens in the respective positions to whic itis adjusted while masking the portions of the sensitized surface otherthan that upon which the image is to be projected.

Signed at Ghicagmlllinois, this 15th day of June, 1929,

ROBERT R. ROBERTSON.

